NASA unveiled a plan Friday to try to redirect an asteroid by flying a spaceship directly into one.

The Double Asteroid Redirection Test, or DART, is a method for changing the path of an asteroid on a collision course with Earth. Essentially, it consists of flying a refrigerator-sized spaceship directly into the asteroid itself, something NASA calls the “kinetic impactor technique.” The test was recently approved by the agency to move from concept development to preliminary design phase, which includes the test itself.

“This approval step advances the project toward an historic test with a non-threatening small asteroid,” Lindley Johnson, planetary defense officer at NASA Headquarters in Washington, said in a NASA press release.

DART will target an asteroid that will pass by Earth in October 2022 and again in 2024. The asteroid, called Didymos (Greek for “twin”) is actually a binary system of two distinct bodies: Didymos A, which is about 780 metres long, and Didymos B, at 160 metres long.

While astronomers watch from Earth, DART will crash directly into Didymos B at a blinding six kilometres per second — nine times faster than a bullet.

“A binary asteroid is the perfect natural laboratory for this test,” Tom Statler, program scientist for DART at NASA Headquarters, said in the release. “The fact that Didymos B is in orbit around Didymos A makes it easier to see the results of the impact, and ensures that the experiment doesn’t change the orbit of the pair around the sun.”

NASA notes in the release that asteroids hit Earth on a near-daily basis, but we don’t tend to notice them because they tend to burn up in the atmosphere. DART is for space rocks that, if they were to hit the planet, would cause substantial damage.

It’s important to test the method on a real asteroid, according to DART investigation co-lead Andy Cheng, because scientists don’t know enough about their composition to visualize the results through calculations alone.

“DART is a critical step in demonstrating we can protect our planet from a future asteroid impact,” Cheng said in the release. “With DART, we can show how to protect Earth from an asteroid strike with a kinetic impactor by knocking the hazardous object into a different flight path that would not threaten the planet.”